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山东省临沂地区杨树人工林地位指数表是于1986年冬至1987年春,收集了25株69杨、72杨和健杨优势木树干解析和104块临时标地材料编制而成。选用lgH=a+b(1/A)公式为导向曲线数学模型;标准年龄定为8a;指数级距2m;级数8个(12—26m)。采用树高相对值法导出各指数级各年龄树高值,经检验此法精度较高,符合生长快、伐期短的杨树生长规律,可供该地区林业部门试用。
The status index of poplar plantations in Linyi Prefecture of Shandong Province was collected from winter solstice to the spring of 1987 in the year of 1986 and collected from 52 trunk poplars, 72 poplar and Jiangyang dominant tree trunks and 104 temporary landmarks. The formula of lgH = a + b (1 / A) is chosen as the mathematical model of the guide curve; the standard age is set as 8a; the index distance is 2m; the number of stages is 8 (12-26m). The tree height relative value method was used to derive the tree height values of all ages in each exponential class. The test proved that the method is accurate, which accords with the growth law of poplar with fast growth and short cutting period, which can be used for trial in the forestry department in this area.